Experiencing the symptoms of Interstitial Keratitis (IK), such as increasing corneal clouding, light sensitivity (photophobia), and pain, can be deeply distressing. When the cornea the clear, front dome of the eye, becomes inflamed, it severely compromises vision and makes daily activities challenging. Interstitial Keratitis is a rare condition that affects the middle layer of the cornea (the stroma), often as a manifestation of a previous or underlying systemic disease, such as a prior infection or an autoimmune disorder.

Treatment is essential to resolve the inflammation quickly, minimize permanent scarring, and preserve vision. If the inflammation persists, the cornea can develop permanent clouding and ghost vessels, severely hindering sight. Because IK is often the eye component of a larger problem, effective treatment must address both the acute inflammation in the eye and the root cause throughout the body. Medication choices depend on the specific underlying condition identified by the doctor (Mayo Clinic, 2023).

Overview of treatment options for Interstitial Keratitis

The primary goals of treating Interstitial Keratitis are twofold: rapidly controlling the inflammation and treating the underlying systemic illness. The overall approach is aggressive medication therapy.

Medication is the standard first-line treatment for IK. The most powerful anti-inflammatory drugs are applied directly to the eye, sometimes for several months, to prevent scarring. For patients with residual scarring that severely limits vision after the inflammation has fully resolved, corneal transplant (keratoplasty) may be considered, but medication is always prioritized first. Treatment duration is typically long-term to ensure the inflammation does not rebound once medications are tapered.

Medications used for Interstitial Keratitis

The first and most critical class of drugs used for IK are Topical Corticosteroids. These powerful anti-inflammatory eye drops, such as prednisolone or dexamethasone, are used to rapidly reduce the swelling and infiltration of inflammatory cells into the corneal stroma. They are the most effective way to clear the clouding and alleviate pain.

Once the underlying cause is identified, specific systemic medications are prescribed to address the root problem:

1. Antiviral Medications: If IK is related to a herpes virus (simplex or zoster), oral antiviral drugs, such as acyclovir or valacyclovir, are used to suppress the virus and prevent recurrence.
2. Antibiotic Medications: If the condition is linked to a bacterial infection like congenital syphilis or Lyme disease, systemic antibiotics (such as penicillin or doxycycline) are necessary to eliminate the bacterial threat.
3. Systemic Immunosuppressants: For bilateral IK linked to severe autoimmune disorders (like Cogan’s syndrome), doctors may prescribe oral or intravenous immunosuppressive agents, such as methotrexate or cyclosporine, to control the body-wide immune attack that is targeting the eye (American Academy of Ophthalmology, 2021).

How these medications work

Corticosteroids work by suppressing the immune system’s inflammatory response. They stop the migration of white blood cells into the cornea and block the release of inflammatory chemicals, which rapidly reduces corneal swelling and pain. This mechanism is crucial for minimizing the formation of permanent scar tissue that would block vision.

Antivirals and antibiotics work by eliminating the specific infectious agents that initially triggered the IK. By removing the trigger, the body is less likely to launch a sustained, damaging immune attack against the cornea. Systemic immunosuppressants modify the overall function of the immune system to interrupt the widespread autoimmune reaction that causes damage to various parts of the body, including the eyes and ears (National Eye Institute, 2022).

Side effects and safety considerations

While vital for saving vision, Topical Corticosteroids carry significant risks, particularly with long-term use. Major concerns are elevated intraocular pressure, risking glaucoma, and cataract development. Treatment demands frequent, close monitoring by an eye specialist.

Systemic drugs also have general side effects. Antivirals may cause nausea or headache. Immunosuppressants can harm liver and kidney function, necessitating regular blood tests. Crucially, topical steroids must not be used with active fungal or amebic eye infections, as they rapidly worsen these conditions. Patients should seek immediate medical help if pain worsens suddenly or vision rapidly declines.

Since everyone’s experience with the condition and its treatments can vary, working closely with a qualified healthcare provider helps ensure safe and effective care.

References

1. American Academy of Ophthalmology. https://www.aao.org
2. Mayo Clinic. https://www.mayoclinic.org
3. National Eye Institute. https://www.nei.nih.gov
4. MedlinePlus. https://medlineplus.gov